/* Copyright (c) 2008, John Cronin
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the copyright holder nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */

/* An extremely simple malloc */

#include "malloc.h"
#include "console.h"
#include "memmgr.h"
#include "kif.h"
#include "stdlib.h"

#define HEAP_SIZE		0x700000
#define HEAP_ALIGN		0x100000

unsigned long int heap_end = 0;
unsigned long int heap_start;

void *malloc(int n)
{
	static unsigned long int cur_end = 0;

	if(cur_end == 0) {
		heap_start = cur_end = (unsigned long int)malloc_align(HEAP_SIZE, HEAP_ALIGN, TLoad, 0);
		heap_end = cur_end + HEAP_SIZE;

		if(cur_end == (unsigned long int)NULL) {
			puts("Error: unable to allocate heap");
			return NULL;
		}

#ifdef _DEBUG
		_puts("heap: ", 0);
		puthex(cur_end);
		_puts("-", 0);
		puthex(heap_end);
		_puts("", 1);
#endif

		add_linked_list(heap_start, HEAP_SIZE, TLoad);
	}

	if((unsigned long int)n > (heap_end - cur_end)) {
		puts("Error: out of heap space");
		return 0;
	}

	cur_end += n;
	return (void *)(cur_end - n);
}

void free(void __attribute__((unused)) *ptr)
{
}
